Not graded
Bulugh al-Maram 1541
وَعَنْهُ قَالَ: قَالَ رَسُولُ اَللَّهِ - صلى الله عليه وسلم -{ مَا قَعَدَ قَوْمٌ مَقْعَدًا لَمْ يَذْكُرُوا اَللَّهَ, وَلَمْ يُصَلُّوا عَلَى اَلنَّبِيِّ - صلى الله عليه وسلم -إِلَّا كَانَ عَلَيْهِمْ حَسْرَةً يَوْمَ اَلْقِيَامَةِ } أَخْرَجَهُ اَلتِّرْمِذِيُّ, وَقَالَ:
"حَسَنٌ"
Abu Hurairah (RAA) narrated that the Messenger of Allah (ﷺ) said:
“If people sit in an assembly in which they do not remember Allah or invoke blessings on the Prophet it will be a cause of grief to them on the Day of Resurrection.” Related by At-Tirmidhi who graded it as Hasan.
Cited in Bulugh al-Maram (No. 1541).